Catalytic reforming with a mixed base catalyst



.nature as contrasted with being regenerable.

United rates 2,854,404 Patented Sept. 30, 1958 ice CATALYTIC REFORMINGWITH A MIXED BASE CATALYST Charles D. Prater and Paul B. Weisz, Pitman,N. J., assignors to Socony Mobil Oil Company, inc, a corporation of NewYork No Drawing. Application September 26, 1955 Serial No. 536,758

Claims. (Cl. $-139) This invention relates to an improved catalyticreforming process for obtaining gasoline of high octane number. Moreparticularly, the present invention is directed to catalytic reformingcarried out in the presence of a catalyst consisting essentially of aparticularly defined mixture of: (1) particles of a porous carrierimpregnated with a small amount of a platinum metal, and (2) particlesof porous eta alumina activated by the presence therein of halogen. Theinvention is further directed to the aforesaid catalyst.

Reforming operations wherein hydrocarbon fractions such as naphthas,gasolines, and kerosine are treated to improve the anti-knockcharacteristics thereof are well known in the petroleum industry.Reforming is generally carried out by contacting the hydrocarbon chargeat an elevated temperature in the presence of hydrogen with a suitablecatalyst. The temperature generally employed in reforming is betweenabout 700 F. and about 1000 F. and more usually between about 800 F. andabout 975 F. The pressure during reforming is generally within the rangeof about 100 to about 1000 p. s. i. g. and preferably between about 200and about 700 p. s. i. g. The liquid hourly space velocity employed, i.e. the liquid volume of hydrocarbon per hour per volume of catalyst, isbetween about 0.1 and about 10 and preferably between about 0.5 andabout 4. In general, the molar ratio of hydrogen to hydrocarbon chargestock employed is between about 1 and about 20 and preferably betweenabout 4 and about 12.

Hydrocarbon charge stocks generally subjected to reforming and thosecontemplated for use in the process of the invention comprise mixturesof hydrocarbons and particularly petroleum distillates boiling withinthe approximate range of 60 F. to 450 F., which range includesgasolines, naphthas, and kerosine. The gasoline fraction may be a fullboiling range gasoline. It is, however, preferred to use a selectedfraction such as naphtha having an initial boiling point of betweenabout 150 F. and about 250 F. and an end boiling point of between about350 F. and about 425 F.

It has heretofore been proposed to employ platinum metal-containingcatalysts for promoting reforming reactions of the type discussed above.Platinum reforming catalysts are necessarily characterized by a certainamount of acidity. One commercially available type of reforming catalystconsists of an alumina base material having platinum metal impregnatedthereon, the acidity characteristic being contributed by small amountsof halogen incorporated in the catalyst. In such catalysts, the halogencomponent is known to be more or less volatile. Activity losses due tohalogen loss are irreversible in It has previously been found asdescribed in co-pending application Serial No. 445,524, filed July 26,1954, by Paul B. Weisz, that the acid and platinum activities may resideon separate particles provided the particle size of each does not exceedabout 100 microns in diameter.

In accordance with the present invention, there is provided an improvedreforming process and catalyst for use therein. Broadly, the catalyst ofthe instant invention is one consisting essentially of a mechanicalmixture of finely divided particles of a porous carrier having depositedthereon a small amount of one or more of the platinum metals, i. e.platinum, palladium, rhodium, osmium, iridium, and ruthenium, and finelydivided particles of porous eta alumina, obtained upon calcining betaalumina trihydrate, having incorporated therein an activating amount ofhalogen, the resulting mechanically mixed catalyst having a minimumdehydrogenation activity (DA) of 50 and a minimum acid activity (AA) of0.2 as hereinafter defined. The invention also provides a process forreforming hydrocarbon fractions boiling in the gasoline range bycontacting them with the above catalyst in the presence of hydrogenunder reforming conditions.

It has heretofore been proposed to reform hydrocarbon fractions bysubjecting the same under reforming conditions with a catalystcomprising a platinum metal supported on an active cracking component.Thus, it has been taught that a platinum metal deposited on a carrier orsupport which is inert as regards cracking activity is not an activecatalyst for reforming operations. It has been discovered, in accordancewith the present invention, that excellent reforming can be achieved inthe presence of a catalyst having a platinum metal deposited on an inertcarrier when the same is combined in the form of amechanical mixturewith a particular crystallographic form of alumina which has beenactivated with halogen. It has been found that the crystallographic formof the alumina with which halogen is combined is an important factorinfluencing the life of the catalyst upon use thereof in reformingoperations. Thus, it has been established, in accordance with thepresent invention, that the loss of halogen, with the accompanyingcatalyst instability, is due to the nature of the crystallographic formof alumina with which the halogen is initially combined. It has beenfound, in accordance with the present invention, that the form ofalumina capable of affording stable operation upon use in reforming isthat identified by X-ray crystallography as eta alumina while the formof alumina which is the less expensive and usual article of commerce isidentifiable as essentially chi alumina, or a mixture of thecrystallographic forms obtained from alpha alumina trihydrate as shownhereinbelow. Such alumina when impregnated with platinum and halogen,does not afford a stable reforming catalyst. It has been discovered thatthe instability differences between the above-mentioned forms of aluminaare due to differences in halogen retentivity of the two forms ofalumina. Thus, the eta form of alumina retains the acidity-producinghalogen most tenaciously and the efficiency of the platinum metalcomponent and its catalytic stability are not substantially different onthe different types of alumina. In accordance with the above findings,it has been established that an effective reforming catalyst may beemployed in which only a portion of the alumina base materialconstitutes the special form of eta alumina containing the halogencomponent and where the remainder of the catalyst material containingthe platinum metal may be made from an inert carrier such as theinexpensive activated alumina of commerce, i. e. chi alumina or aluminaderived upon calcination from alpha alumina trihydrate.

It has been discovered, in accordance with the present invention, that amechanical mixture of particles of a porous inert carier having platinummetal deposited thereon and particles of eta alumina activated by thepresence therein of halogen may be advantageously employed in reformingoperations, providing the resultant catalyst composite is characterizedby a specified minimum dehydrogenation and acid activity. Thus, it hasbeen found that hydrocarbon fractions having low octane ratings can beconverted into hydrocarbon fractions having high octane ratings in goodyields by subjecting them to reforming in the presence of hydrogen and acatalyst of the aforesaid character.

'The' dehydrogenation activation (DA) index characterizing the catalystdescribed herein measures the catalytic efficiency of thedehydrogenation component of the catalyst. In platinum-containingreforming catalysts, it represents the catalytic strength of theplatinum in the form contained on the carrier. In evaluatingdehydrogenation activity, a small amount of catalyst sample, forexample, l5 milligrams, deposited on a boat as 100-200 mesh powder isintroduced into a glass reactor tube. Cyclohexane and hydrogen atatmospheric pressure are passed over the catalyst at a rate of 55.2 cc.liquid cyclohexane per hour and hydrogen in a molar ratio of 4:1 ofhydrogen to hydrocarbon. The catalyst temperature is maintained at 806 IThe product liquid is analyzed for benzene by a mass spectrometer and,from its concentration, the rate of formation of benzene in units ofmoles/ second per gram catalyst sample is calculated. The number isdesignated as the dehydrogenation activity or DA index. The acidactivity (AA) index measures the catalytic strength of the-acid, i. e.,the halogen containing component of the catalyst. The test reaction usedis the rate of gas production from cumene (isopropylbenzene), whichproceeds at a rate dependent on the acidity of the catalyst. Thepresence or absence of the platinum component does not interferesignificantly with the measurement, which is done at atmosphericpressure in the absence of hydrogen. In evaluating acid acivity, a smallamount of catalyst sample, usually about 150 milligrams contained in aboat as 100200 mesh powder is employed. Cumene is passed over thecatalyst at a rate of about 100 cc./hour and the reaction rate isobtained directly from the rate of gas production at a catalysttemperature of 788 F. The result is expressed as the acid activity or AAindex, such that it expresses the absolute rate of cracking in units of10 moles of gas per gram of catalyst per second.

It has been established, in accordance with the present invention, thatthe mechanical catalyst composite consisting essentially of particles ofan inert carrier having a platinum metal deposited thereon and particlesof eta alumina containing halogen should essentially be characterized bya dehydrogenation activity in an excess of about 50 and an acid acivitygreater than about 0.2. More particularly, it is prefe'red that thedehydrogenation activity be within the range of 100 to 5000 and the acidactivity be within the range of 0.2 to 8 and especially within the rangeof 0.2 to 5.

It is contemplated that the carrier employed as a support forthe'platinum metal component may be any porous material which is notadversely affected by the temperature conditions of reforming. Thecarrier desirably has a surface area greater than about 10 square 1meters per. gram and preferably in excess of 30 square metersxper gramand may extend up to 500 square meters per gram or more. The termsurface area as used herein designates the surface area of the carrieras determined by. the adsorption of nitrogen according to the method ofBrunnauer et al., Journal American Chemical Society 60, 309 .et. seq.(1938). The carrieris suitably inert, i. e.,.it may itself beessentially devoid of or exert negligible catalytic activity under thereaction conditions of reforming. Suitable carriers include singleoxides of the metals of groups II-A, III-B, IV-A, and IV-B of theperiodic table. Non-limiting examples thereof include zirconia, titania,silica, magnesia, etc. Other suitable inert materials include charcoal,porous glass, porcelain,-pumice, coke, activated carbon, bauxite, inertearths, etc. .The density of the carrier employed, i. e., the bulkdensity thereof will usually be within the 4 range of .2 to 2.0 g./cc.and more particularly between about .4 and about 1.2 g./cc.

In particular, it is preferred to employ an alumina carrier for theplatinum metal. The alumina carrier may be in the form of a precipitateor a gel. Various forms of alumina either singly or in combination, suchas, eta, chi, gamma, theta, delta or alpha alumina may be suitablyemployed as the alumina carrier. The above nomenclatureused in .thepresent specification andclaims with reference to alumina phasedesignation is that generally employed in the United States anddescribed in The Aluminum Industry: Aluminum and Its Production byEdwards, Frary, and Jeifries, published by Me- Graw-Hill (1930). Thevarious above-designated phases of alumina, including occurrence innature, preparation, phase transitions, crystal structure, and physicalproperties are described in detail in Alumina Properties," by A. S.Russell, Aluminum Company of America, Pittsburgh (1953). A preferredembodiment of the invention is the use of inexpensive readily availableactivated alumina of commerce as the base for the platinum metal. Thisform of alumina is obtained by the controlled calcination of alphaalumina trihydrate, which occurs naturally and which is also the productof the Bayer process. The decomposition sequence of alpha aluminatrihydrate, upon heating 1 hour in dry air, is as follows:

0. 280 C. Alpha trihydrate alpha monohydrate --v 260 C. I 450 C. 500 C.1020 0. ch! --v gamma 1080 C. 50 0. kappa theta t alpha 1120 C. 1180 C.

where the upper numbers show the temperature at which the next phasestarts to form and the bottom numbers show the temperature at whichtransformation is complete. Activated alumina contains as its principalconstituents chi and gamma alumina, the relative concentration of eachdepending upon the degree of calcination.

In contrast to the foregoing preferred use of a carrier of inexpensiveactivated alumina derived from the calcination of alpha aluminatrihydrate, is the use of the eta form of alumina, which is obtainedupon calcining beta alumina trihydrate. The latter does not occur innature and accordingly is necessarily produced by synthetic means, suchas by treating aluminum chloride solutions with ammonium hydroxide inthe cold, followed by syneresis at room temperature, by saturating asolution of sodium aluminate with carbon dioxide at room temperature, orby the action of water on finely divided or amalgamated aluminum. All ofthese methods forpreparing beta alumina trihydrate are relativelyexpensive. Consequently, the manufacture of eta alumina obtainedtherefrom is likewise expensive. The decomposition sequence of betaalumina trihydrate, upon heating 1 hour in dry air, is as follows:

140C. j 250C. Beta trihydrate alpha monbhydrate -'r 240 C. 450 0.

800 C. 1180 C. eta theta alpha 850 C. 1250 C. V

where the upper numbers show the temperature at which the next phasestarts to form and the bottom numbers show the temperature at whichtransformation is complete. 1

In accordance with the present invention, it has been found that etaalumina retains acidity-producing halogen more tenaciously than variousother forms of alumina, such as the chi and gamma aluminas. With use ofthe present mechanical catalyst mixture, however, the necessary acidactivity is divorced from the platinum metalcontaining component,permitting a wide' choice of porous inert carrier for such metal andmaking possible use of the readily available activated alumina derivedfrom alpha alumina trihydrate. It is accordingly a particularlypreferred embodiment of the invention to employ a carrier of suchactivated alumina for the platinum metal.

The porous inert carrier serves as a support for a catalyticallyeffective amount of a platinum metal, i. e., platinum, palladium,rhodium, osmium, iridium and ruthenium as well as alloys of thesemetals. Of the foregoing, platinum and palladium, and in particularplatinum, are accorded preference. The amount of platinum metalcontained in the ultimate catalyst is generally between about 0.05 andabout 5 percent by weight and, in particular, between about 0.1 andabout 2 percent by weight.

It has been established, in accordance with the present invention, that,while the platinum metal is suitably deposited on a porous inertsupport, the acidic portion of the catalyst, that is, the portioncontaining halogen, should consist of a particular form of alumina,namely, eta alumina. Such form of alumina, as indicated above, isobtained upon calcination of beta alumina trihydrate. This form ofalumina has been found to posesses unexpected properties with referenceto the retention of added halogen and, in this regard, has the abilityto retain halogen to a much greater degree, particularly at the elevatedtemperatures encountered in reforming, over various other forms ofalumina, such as the aforementioned chi and gamma aluminas'.

It is contemplated that halogen ion may be added to the eta form ofalumina in any feasible manner. However, the halogen should be added ina form which will readily react with the alumina in order to obtain thedesired results. One suitable method of adding the halogen is in theform of an acid, such as hydrogen fluoride, hydrogen chloride, hydrogenbromide, and/or hydrogen iodide. Hydrogen fluoride is preferably addedin the form of an aqueous solution. Other suitable means for adding thehalogen is in the form of volatile salts, such as ammonium fluoride,ammonium chloride, etc. The ammonium ions will be removed during thesubsequent heating of the catalyst and therefore will not leaveundesirable deposits in the catalyst. Also, the halogen may be added asfluorine, chlorine, bromine, or iodine, or by treatment in gaseoushydrogen halide. The concentration of halogen ion introduced into theeta alumina is such that the ultimate dry catalyst will have a halogencontent within the range from about 0.1 to about 8 and preferably fromabout 0.1 to about 5 percent by weight.

In accordance with the present invention, the weight fraction of inertcarrier supporting the platinum metal may vary widely, thereby affordingdesirable flexibility in the catalyst composition which may be variedwith the specific charge stock undergoing treatment and with theparticular reaction conditions under which the reforming operation iseffected. In general, however, the relative weight fractions of theinert carrier impregnated with a platinum metal and the halogenactivated eta alumina component of the instant catalyst is between about0.1

and about 0.9.

The particle size of the components comprising the catalyst mixture ofthis invention has been found to be a critical feature thereof. It hasbeen established that, for optimum reforming with the desired catalyst,the average particle size of each of the components making up saidcatalyst should be less than about 100 microns. It is accordinglycontemplated that the catalyst of this invention will in generalcomprise particles having a diameter below 100 microns and particularlya diameter in the approximate range of 1 to 100 microns.

Without being limited by any theory, it is believed that the optimumresults achieved herein with finely divided particles are due to theaccomplishment of the two reactions important in reforming, namely,isomerization 6 and aromatization, by way of olefinic intermediates inaccordance with the following reaction steps:

(2) Paraflin olefin aromatic It is believed that each reaction stepmarked by 0 takes place on a dehydrogenation center, such as a platinummetal, while each step marked by O takes place on an acid catalystcenter. It is postulated that the two components comprising the instantcatalyst mixture, i. e., particles of the platinum metal deposited on aninert carrier and particles of halogen activated eta alumina, shouldpresent sufiicient reaction surface and be sufficiently proximate to oneanother that the olefinic intermediates formed during the reactionproceed to the desired isomerized or aromatized end products during thelife-time of such intermediates. It has been established that optimumreforming is attained when the particle size of the components making upthe instant catalyst is fairly small and specifically less than aboutmicrons in diameter.

The catalyst of this invention may be used in the form of discreteparticles having the aforesaid requisite diameter, or the componentshaving such particle size may be admixed and pelleted, cast, molded, orotherwise formed into pieces of desired size and shape, such as rods,spheres, pellets, etc., it being essential, however, that each of saidpieces is composed of particles of both components having a particlediameter of less than about 100 microns.

The process of this invention can be carried out in any equipmentsuitable for catalytic operations. The process may be operatedbatchwise. It is preferable, however, and generally more feasible tooperate continuously. Accordingly, the process is adapted to operationsusing a fixed bed of catalyst. Also, the process can be operated using amoving bed of catalyst wherein the hydrocarbon flow may be concurrent orcountercurrent to the catalyst flow. A fluid type of operation whereinthe catalyst is carried out in suspension in the hydrocarbon charge iswell adapted for use with the instant catalyst since pelleting orotherwise shaping of the catalyst components is thus renderedunnecessary.

The carrier for the platinum metal component of the instant catalyst, asindicated hereinabove, is inert with respect to the reforming ofhydrocarbons, i. e., it is not effective in catalytic reformingoperations under the conditions of the process of this invention. Anumber of platinum-containing reforming catalysts have heretofore beenproposed wherein the platinum metal is impregnated on an alumina base.However, inasmuch as the alumina is not acidic, it has heretofore beenthe practice to combine the alumina upon which the platinum is depositedwith promoting agents, such as halogens, boria, and the like. It is wellknown that such promoters are not permanent but may be lost upon contactwith water vapor which is inherently or accidentally contained withinthe hydrocarbon feed stock.

Utilizing one embodiment of this invention, it is now possible 'toisolate the halogen-promoted portion of the catalyst since the halogenacid centers are located on separate particles of eta alumina distinctfrom the par- .ticles of inert carrier employed for the platinum metalcomponent. Thus, should a catalyst of the present invention becomedeactivated due to the loss of halogen therefrom by accidental contactwith water vapor, it is only necessary to activate a portion of thecatalyst, i. e. the eta alumina particles, by removing the same from thecatalyst mixture, treating with halogen to bring the overall halogencontent thereof up to the desired amount and subsequently re-combiningthe halogen treated eta alumina with the platinum metal component. Itwill be evident that in such manner the portion of the catalystcontainingi the 'yaluable platinum metal is not subjected "to'activatingor'other'p'ro'cessing treatment whichwould serve to induce a loss of thevaluable metal.

The platinum metal may be deposited on the carrier in any suitablemanner. One feasible method is to admixparticles of the carrier with anaqueous solution of' an acid of the metal, for example, chloroplatinicacid or the ammonium salt of such acid of suitableconcentration- Theimpregnated particles are then dried and treated with hydrogenatelevatedtemperatures-to reduce the oxide to the metal and toactivate-the catalyst.

It is contemplated .that the halogen-activatedeta alumina component ofthepresent catalyst may be'qproduced by. treatingeta alumina withhalogen or ahalogen-compound by:any of the usual methods. Thus, asdescribed above, the'eta alumina maybetreated with a hydrogenhalide-.01. ammonium salt of such acid to introduce into Example 1 Acatalyst was prepared by impregnating 100 grams of chi alumina with 3.10grams of chloroplatinic acid solution containing 40 percent by weight ofplatinum. Contactbetween chi alumina and impregnating solution wasmaintained for 48 hours. Thereafter, the impregnated particles wereremoved, dried in air for 2 hours at 130 C. and ground to approximately100 mesh (Tyler). or smaller. The resulting powder was'treated for 2hours in air at 510 C. and thereafter treated for 2 hours'in hydrogen at510 C.

The halogen-containing component of the catalyst was prepared by addingto 88.5 grams of powdered beta alumina trihydrate suspended in 100 cc.of water, 126 grams of aqueous HF solution containing 1.19 percent byweight of HP. The alumina powder was maintained in contact with theimpregnating solution for 1 hour with agitation. The impregnated powderwas thereafter dried in air for 16 hours at 130 C. and thereaftercalcined for 2 hours in nitrogen at 200 C.-250 C., followed by treatingfor 2 hours in nitrogen at 510 C.

The platinum-containing component and the halogencontaining componentwere mixed in equal weight proportion andball-milled as a 75 percent byweight water slurry until an average particle size of approximately 5microns was obtained. The resulting material was dried at 150 C. andpelleted.

The resulting catalyst pellets were charged to a reforming unit operatedat 500 p. s. i. g., /1 hydrogen to, hydrocarbon ratio utilizing a chargestock of naphtha having-an octane .number of 64.9 and a temperaturewithin the range of 880 F. to 910 F.-adjusted to maintain productionof98 octane number (3 cc. of TEL) reformate. The catalyst was stableover a period of 38 days and even at the end of this time showed notendency of becoming unstable.

I Example 2 A catalyst composite was made by the methods employed inExample 1 except that the platinum on chi alumina component was steamedto remove any chlorine introduced therein as a result of impregnatingwith chloroplatinic acid. 279.5 grams of beta alumina trihydrate weresuspended in 200 cc. of water. To this was added 294 grams of aqueous HFsolution containing 1.19% by weight of HF to introduce into the aluminaan amount of fluorine corresponding to a fluorine content of 1.4 weightpercent of the ultimate catalyst on a dry basis.

The fluorinated beta alumina was then dried for 16 hours:

at"135 C. and thereafter heated innit'rogen'for 1% hours at 232 C., 2'hours in'nitrogen'at 510 C., and' 2 hours in hydrogen at 510 C.Theplatinum-containing component and the halogen-containing componentwere mixed in .equal weight proportion by ball-milling the components ina dry state.

This catalyst, when tested under conditions identical .to' thoseemployed in Example 1, gave a 98 octanenumber product when operated atan average inlet temperature to the temperature of 874 gasoline of 91.8volume percent of naphtha charged.

- This catalyst possessed excellent stability over a periodv of days andeven at the end of this time showed no tendency of becoming unstable. I

From the foregoing examples, it will be seen that the mechanicalcatalyst mixture of this invention consisting of halogen activated etaalumina mixed with platinum impregnated chi alumina is an effectivecatalyst for use in the reforming of hydrocarbons. In addition to theforegoing, other test and demonstrate the adequacy of the inexpensivechi alumina as a support for the platinum component have been made. Inthe table below, there is set forth a comparison of samples of platinumimpregnated on chi alumina, with platinum impregnated on eta alumina,when'these were subjected to severe thermal treatments to test thethermal stability of the catalytic strength of the I platinum.

After Heat After Heat Before Treatment Treatment at 650C. at 760C.

Platinum on eta alumina 1, 350 18 Platinum on chi alumina (Platinumcomponent of Catalyst 0! Example 1)- 1,630 304 250 In the above table,the DA index expresses the catalytic dehydrogenation activity. of theplatinum. It will be seen from the tabulated data that the thermalstability of platinum on chi alumina is as good if not better thanthethermal stability of platinum on eta'alumina.

. The ability to choose the amount of halogen-activated eta alumina andthe amount of platinum component making up the ultimate catalyst mixturehas the advantage that the amount of acidity, as'well as the amount ofplatinum metal contained in the catalyst, can be controlled not only bythe respective concentrations of the halogen'and platinum impregnatingsolutions used but also by the respective amounts of thehalogen-promoted eta alumina and the platinum metal component of the"catalyst. If the two-component catalyst of this invention is used in theform of a mixture of fluidized particles, the two components of themixture will be physically independent. Accordingly, a process usingcatalysts in this form affords complete and immediate flexibility incatalyst composition within the limits set forth hereinabove. Thus inchanging types of charge stocks such as between paraflinic andnaphthenic stocks, the catalyst composition can be adjusted inaccordance with this invention by adding or withdrawing one or the othercatalyst component. For example, in transferring to more naphtheniccharge stocks, a greater proportion of halogen-activated eta aluminacomponent in the present catalyst mixture will serve to increase theyield of C gasoline. On the other. hand, in transferring to paratfinicstocks, a relatively greater emphasis on the platinum metal component isdesirable to reduce the cracking reaction and to emphasizedehydrocyclization.

The fact that the platinum metal and halogen-activated mechanicalcatalyst mixtures have generally diflerent reactor of 900 F. or anaverage catalyst F. with a yield of 10 pounds RVP measurements designedto' properties on the one hand but are seen to be operable as physicallyindependent or separable entities on the other hand affords a basis forimproving reforming processes with regard to catalyst regeneration andmethods for the recovery of the valuable platinum metal constituents ofthe catalyst after the same has become catalytically spent.

As regards advantages in regeneration, platinum-containing reformingcatalysts of the type heretofore employed in which platinum isimpregnated on a cracking base have been regenerated by contacting thespent catalyst with air or other oxygen-containing gas at an elevatedtemperature sufiicient to burn carbonaceous deposits from the catalysts.Careful control of the rate of burning, temperature, and water contentof the gas atmosphere during regeneration of such catalysts have beennecessary in order not to impair the activity of the catalyst. We havefound that conditions and limitations for the operating variables inregeneration are quite distinct and difierent for the preservation ofthe acidic and of the platinum activities of such catalysts. Forexample, the presence of water vapor will cause a loss of halogenconcentration resulting in loss of reforming activity, while theplatinum itself does not lose its activity. On the other hand highconcentration of oxygen and high temperatures will often reduce theeffectiveness of the platinum.

By utilizing the mechanical catalyst mixture of this invention, it ispossible to provide separate and optimum means for ready regeneration ofeach of the two components. Thus, the catalyst of the present invention,after becoming spent, may be separated into its components of platinummetal-containing particles and halogen-activated eta alumina particlesby providing such components with a suitable different physicalcharacteristic which permits their ready separation, such as adifference in particle size. In those instances where a pelletedcomposite of halogen-activated eta alumina component andplatinum-containing component is employed, the catalyst mixture may beseparated into its components by initially crushing to a particle sizecomparable to or below the magnitude of the small constituent particlesand thereafter separating the component particles by flotation,air-blowing, sifting, or by any of the various other known means forseparating physically and/or chemically different materials. Theseparated halogen-activated eta alumina particles and platinumcontainingcomponents may then be separately regenerated, under conditions bestsuited for each.

The present invention thus provides a process for catalytic reformingand a catalyst for use therein consisting of a mechanical mixture ofparticles of halogen-activated eta alumina and particles of an inertcarrier having a platinum metal deposited thereon. It is an essentialfeature of the invention that the halogen be restricted to the specialeta form of alumina and that platinum be deposited on a separate inertcarrier, preferably of chi alumina. Thus, a reforming catalyst isprovided consisting of a mechanical mixture of particles of aluminaactivated by halogen and of particles of alumina bearing platinumwherein only the former component constitutes the crystallographic formknown as eta alumina.

It is to be understood that the above description is merely illustrativeof preferred embodiments of the invention, of which many variations maybe made within the scope of the following claims by those skilled in theart without departing from the spirit thereof.

We claim:

1. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) a porousinert carrier having deposited thereon an amount of platinum metal suchthat the ultimate catalyst has a platinum metal content of between about0.05 and about 5 percent by weight and (2) eta alumina activated withhalogen in an amount such that the ultimate catalyst has a halogencontent of between about 0.1 and about 8 percent by weight, the relativeweight fractions of the two components being between about 0.1 and about0.9 and the relationship between said components being such that theresultant mixture is characterized by a dehydrogenation activity of atleast 50 and an acid activity of at least 0.2.

2. A process for reforming a petroleum distillate boiling within theapproximate range of 60 F. to 450 R, which comprises contacting the sameat a temperature between about 700 F. and about 1000 F. at a liquidhourly space velocity between about 0.1 and about 10 in the presence ofhydrogen under a pressure between about and about 1000 p. s. i. g. and amolar ratio of hydrogen to hydrocarbon between about 1 and about 20 witha catalyst consisting essentially of a mechanical mixture of particlesof less than about 100 microns in diameter of: l) a porous inert carrierhaving deposited thereon an amount of platinum metal such that theultimate catalyst has a platinum metal content of between about 0.05 andabout 5 percent by weight and (2) eta alumina activated with halogen inan amount such that the ultimate catalyst has a halogen content ofbetween about 0.1 and about 8 percent by Weight, the relative weightfractions of the two components being between about 0.1 and about 0.9and the relationship between said components being such that theresultant mixture is characterized by a dehydrogenation activity of atleast 50 and an acid activity of at least 0.2.

3. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (l) porousactivated alumina derived from alpha alumina trihydrate having depositedthereon an amount of platinum metal such that the ultimate catalyst hasa platinum metal content of between about 0.05 and about 5 percent byweight and (2) eta alumina activated with halogen in an amount such thatthe ultimate catalyst has a halogen content of between about 0.1 andabout 8 percent by weight, the relative weight fractions of the twocomponents being between about 0.1 and about 0.9 and the relationshipbetween said components being such that the resultant mixture ischaracterized by a dehydrogenation activity of at least 50 and a weightactivity of at least 0.2.

4. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) porousactivated alumina consisting essentially of chi and gamma alumina havingdeposited thereon an amount of platinum metal such that the ultimatecatalyst has a platinum metal content of between about 0.05 and about 5percent by weight and (2) eta alumina activated with halogen in anamount such that the ultimate catalyst has a halogen content of betweenabout 0.1 and about 8 percent by weight, the relative weight fractionsof the two components being between about 0.1 and about 0.9 and therelationship between said components being such that the resultantmixture is characterized by a dehydrogenation activity of at least 50and an acid acivity of at least 0.2.

5. A process for reforming a petroleum distillate boiling within theapproximate range of 60 F. to 450 R, which comprises contacting the sameat a temperature between about 700 F. and about 1000 F. at a liquidhourly space Velocity between about 0.1 and about 10 in the presence ofhydrogen under a pressure between about 100 and about 1000 p. s. i. g.and a molar ratio of hydrogen to hydrocarbon between about 1 and about20 with a catalyst consisting essentially of a mechanical mixhalogencontent of between about 0.1 and about 8 percent by weight, the relativeweight fractions of the two com ponents being between about 0.1 andabout 0.9 and the relationship between said components being such thatthe resultant mixture is characterized by a dehydrogenation activity ofat least 50 and an acid activity of at least 0.2.

6. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) chi aluminahaving deposited thereon an amount of platinum such that the ultimatecatalyst has a platinum metal content of between about 0.1 and about 2percent by weight and (2) eta alumina activated with chlorine in anamount such that the ultimate catalyst has a chlorine content of betweenabout 0.1 and about 5 percent by Weight, the relative weight fractionsof the two components being between about 0.1 and abou 0.9 and therelationship between said components being such that the resultantmixture is characterized by a dehydrogenation activity of at least 50and an acid activity of at least 0.2.

7. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) chi aluminahaving deposited thereon an amount of platinum such that the ultimatecatalyst has a platinum metal content of between about 0.1 and about 2percent by weight and (2) eta alumina activated with fluorine in anamount such that the ultimate catalyst has a fluorine content of betweenabout 0.1 and about 5 percent by weight, the relative weight fractionsof the two components being between about 0.1 and about 0.9 and therelationship between said components being such that the resultantmixture is characterized by a dehydrogenation activity of at least 50and an acid activity of at least 0.2.

8. A process for reforming a hydrocarbon mixture boiling in the gasolinerange, which comprises contacting the same under reforming conditionswith a catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) chi aluminahaving deposited thereon an amount of platinum such that the ultimatecatalyst has a platinum content of between about 0.1 and about 2 percentby weight and (2) eta alumina activated with fluorine in an amount suchthat the ultimate catalyst has a fluorine content of between about 0.1and about 5 percent by weight, the relative weight fractions of the twocomponents being substantially equal and the relationship between saidcomponents being such that the resultant mixture is characterized by adehydrogenation activity of between about 100 and about 5000 and an acidactivity of between about 0.2 and about 8.

9. A catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (l) a porousinert carrier having deposited thereon an amount of platinum metal suchthat the ultimate catalyst has a platinum metal content of between about0.05 and about 5 percent by weight and (2) eta alumina activated withhalogen in an amount such that the ultimate catalyst has a halogencontent of between about 0.1 and about 8 percent by weight, the relativeweight fractions of the two components being between about 0.1 and about0.9 and the relationship between said components being such that theresultant mixture is characterized by a dehydrogenation 1 2 activity' ofatleast 50 and an acid activity ofat least 0.2; V p j p 10. 'A' catalystconsisting mixture of par'ticles of less than about 100 microns indiameter of: (l) porous activated alumina derived from alphaalumina'trihydrate having deposited thereon an amount of platinum metalsuch that the ultimate cata ly st hasxa platinum metal content ofbetween about 0.05 and about 5 percent by weight and (2) eta aluminaactivated with halogen in an amount such that the ultimate catalyst hasa halogen content of between about 0.1 and about 8 percent by weight,the relative weight fractions of the two components being between about0.1 and about 0.9' and the relationship between said components beingcharacterized by a dehydrogenation activity 50 and a weight'activity ofat least 0.2.

11. A catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (1) porousactivated alumina consisting essentially of chi and gamma alumina havingdeposited thereon an amount of platinum metal such that the ultimatecatalyst has a platinum metal content of between about0.05 and about 5percent by weight and (2) eta alumina activated with halogen in anamount such that of at least the ultimate catalyst has a halogen contentof between said components being such that the resultant mixture ischaracterized by a dehydrogenation activity of at least 50 and anacid'activity of at least 0.2.

12. A catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (l) chi aluminahaving deposited thereon an amount of platinum such that the ultimatecatalyst has a platinum content of between about 0.05 and about 5percent by weight and (2) eta alumina activated with halogen in anamount such that the ultimate catalyst has a halogen content of betweenabout 0.1 and about 8 percent by weight, the relative weight fractionsof the two components being between about 0.1 and about 0.9 and therelationship between said components being such that the resultantmixture is characterized by a dehydrogenation activity of at least 50and an acid activity of at least 0.2.

' 13. A catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in diameter of: (l) chi aluminahaving deposited thereon an amount of platinum such that the ultimatecatalyst has a platinum metal content of between about 0.1 and about 2percent by weight and (2) eta alumina activated with chlorine in anamount such that the ultimate catalyst has a chlorine content of betweenabout 0.1 and about 5 percent by weight, the relative weight fractionsof, the two components being between about 0.1 and'about 0.9 and therelationship between said components being characterized by adehydrogenation activity of at least 50 and an acid activity of at least0.2.

14. A catalyst consisting essentially of a mechanical mixture ofparticles of less than about 100 microns in about 5 percent by weight,the relative weight fractions of the two components being between about0.1 and about 0.9 and the relationship between said components beingsuch that the resultant mixture is characterized by a dehydrogenationactivity of at least 50 and an acid activity of at least 0.2.

15. A catalyst consisting essentially of a mechanical essentially of amechanical such that the resultant mixture is such that the resultantmixture is mixture of particles of less than about 100 microns indiameter of: 1) chi alumina having deposited thereon an amount ofplatinum such that the ultimate catalyst has a platinum content ofbetween about 0.1 and about 2 percent by weight and (2) eta aluminaactivated with fluorine in an amount such that the ultimate catalyst hasa fluorine content of between about 0.1 and about 5 percent by Weight,the relative weight fractions of the two components being substantiallyequal and the relationship between said components being such that theresultant mixture is characterized by a dehydrogenation activity ofbetween about 100 and about 5000 and an acid activity of between about0.2 and about 8.

References Cited in the file of this patent UNITED STATES PATENTS2,369,009 Block et al. Feb. 6, 1945 2,479,109 Haensel Aug. 16, 19492,642,381 Dickinson June 16, 1953 2,746,909 Hemminger May 22, 19562,780,603 Burton Feb. 5, 1957

1. A PROCESS FOR REFORMING A HYDROCARBON MIXTURE BOILING IN THE GASOLINERANGE, WHICH COMPRISES CONTACTING THE SAME UNDER REFORNING CONDITIONWITH A CATALYST CONSISTING ESSENTIALLY OF A MECHANICAL MIXTURE OFPARTICLES OF LESS THAN ABOUT 100 MICRONS IN DIAMETER OF : (1) A POROUSINERT CARRIER HAVING DEPOSITED THEREON AN AMOUNT OF PLATINUM METAL SUCHTHAT THE ULTIMATE CATALYST HAS A PLATINUM METAL CONTENT OF BETWEEN ABOUT0.05 AND ABOUT 5 PERCENT BY WEIGHT AND (2) ETA ALUMINA ACTIVATED WITHHALOGEN IN AN AMOUNT SUCH THAT THE ULTIMATE CATALYST HAS A HALOGENCONTENT OF BETWEEN ABOUT 0.1 AND ABOUT 8 PERCENT BY WEIGHT, THE RELATIVEWEIGHT FRACTIONS OF THE TWO COMPONENTS BEING BETWEEN ABOUT 0.1 AND ABOUT0.9 AND THE RELATIONSHIP BETWEEN SAID COMPONENTS BEING SUCH THAT THERESULTANT MIXTURE IS CHARACTERIZED BY A DEHYDROGENATION ACTIVITY OF ATLEAST 50 AND AN ACID ACTIVITY OF AT LEAST 0.2.